AUTHOR=Ayayee Paul A. , Petersen Nick , Riusch Jennifer , Rauter Claudia , Larsen Thomas 

TITLE=Enhanced gut microbiome supplementation of essential amino acids in Diploptera punctata fed low-protein plant-based diet

JOURNAL=Frontiers in Insect Science

VOLUME=4

YEAR=2024

URL=https://www.frontiersin.org/journals/insect-science/articles/10.3389/finsc.2024.1396984

DOI=10.3389/finsc.2024.1396984

ISSN=2673-8600

ABSTRACT=<sec><title>Introduction</title><p>Building on our previous work, we investigate how dietary shifts affect gut microbial essential amino acid (EAA) provisioning in the lactating cockroach <italic>Diploptera punctata</italic>.</p></sec><sec><title>Method</title><p>To that end, we fed cockroaches three distinct diets: a plant-only Gari diet composed of starchy and granulated root tuber Yucca (<italic>Manihot esculenta</italic>), a dog food diet (DF), and a cellulose-amended dog food (CADF) diet. We anticipated that the high carbohydrate, low protein Gari would highlight increased microbial EAA supplementation to the host.</p></sec><sec><title>Results</title><p>By day 28, we observed distinct profiles of 14 bacterial families in the insect gut microbiomes of the three dietary groups. CADF-fed insects predominantly harbored cellulolytic and nitrogen-fixing bacteria families <italic>Streptococcaceae and Xanthomonadaceae</italic>. In contrast, Gari-fed insects were enriched in anaerobic lignocellulolytic bacteria families <italic>Paludibacteraceae</italic> and <italic>Dysgonomonadaceae</italic>, while DF-fed insects had a prevalence of proteolytic anaerobes <italic>Williamwhitmaniaceae</italic> and sulfate-reducing bacteria <italic>Desulfovibrionaceae</italic>. Furthermore, we confirmed significantly higher EAA supplementation in Gari-fed insects than in non-Gari-fed insects based on δ<sup>13</sup>C-EAA offsets between insect and their diets. The δ<sup>13</sup>C-EAA offsets between DF and CADF were nearly indistinguishable, highlighting the relevance of using the plant-based Gari in this experiment to unequivocally demonstrate this function in this insect. These results were underscored by lower standard metabolic rate (SMR) relative to the DF insect in Gari-fed (intermediate SMR and dietary quality) and CADF (least SMR and dietary quality) insects.</p></sec><sec><title>Discussion</title><p>The influence of diet on EAA provisioning and SMR responses in insects underscores the need for further exploration into the role of gut microbial functions in modulating metabolic responses</p></sec>